Use f-strings where possible

gridlock/draw.py

@@ -48,7 +48,7 @@ def draw_polygons(self,
     surface = numpy.delete(range(3), surface_normal)
 
     for i, polygon in enumerate(polygons):
-        malformed = 'Malformed polygon: (%i)' % i
+        malformed = f'Malformed polygon: ({i})'
         if polygon.shape[1] not in (2, 3):
                 raise GridError(malformed + 'must be a Nx2 or Nx3 ndarray')
         if polygon.shape[1] == 3:
@@ -106,9 +106,9 @@ def draw_polygons(self,
             # evaluate on the meshgrid
             eps_i = eps[i](x0, y0, z0)
             if not numpy.isfinite(eps_i).all():
-                raise GridError('Non-finite values in eps[%u]' % i)
-            raise GridError('Unsupported eps[{}]: {}'.format(i, type(eps[i])))
+                raise GridError(f'Non-finite values in eps[{i}]')
         elif numpy.size(eps[i]) != 1:
+            raise GridError(f'Unsupported eps[{i}]: {type(eps[i])}')
         else:
             # eps[i] is scalar non-callable
             eps_i = eps[i]
@@ -232,7 +232,7 @@ def draw_slab(self,
         if len(center) == 3:
             center = center[surface_normal]
         else:
-            raise GridError('Bad center: {}'.format(center))
+            raise GridError(f'Bad center: {center}')
 
     # Find center of slab
     center_shift = self.center
@@ -331,7 +331,7 @@ def draw_extrude_rectangle(self,
     if s == 0:
         raise GridError('0 is not a valid polarity')
     if direction not in range(3):
-        raise GridError('Invalid direction: {}'.format(direction))
+        raise GridError(f'Invalid direction: {direction}')
     if rectangle[0, direction] != rectangle[1, direction]:
         raise GridError('Rectangle entries along extrusion direction do not match.')
 

gridlock/grid.py

@@ -279,7 +279,7 @@ class Grid:
 
         for i in range(3):
             if len(self.exyz[i]) != len(pixel_edge_coordinates[i]):
-                warnings.warn('Dimension {} had duplicate edge coordinates'.format(i), stacklevel=2)
+                warnings.warn(f'Dimension {i} had duplicate edge coordinates', stacklevel=2)
 
         if isinstance(periodic, bool):
             self.periodic = [periodic] * 3
@@ -288,10 +288,10 @@ class Grid:
 
         if len(self.shifts.shape) != 2:
             raise GridError('Misshapen shifts: shifts must have two axes! '
-                            ' The given shifts has shape {}'.format(self.shifts.shape))
+                            f' The given shifts has shape {self.shifts.shape}')
         if self.shifts.shape[1] != 3:
             raise GridError('Misshapen shifts; second axis size should be 3,'
-                            ' shape is {}'.format(self.shifts.shape))
+                            f' shape is {self.shifts.shape}')
 
         if (numpy.abs(self.shifts) > 1).any():
             raise GridError('Only shifts in the range [-1, 1] are currently supported')

gridlock/position.py

@@ -46,7 +46,7 @@ def ind2pos(self,
             low_bound = -0.5
             high_bound = -0.5
         if (ind < low_bound).any() or (ind > self.shape - high_bound).any():
-            raise GridError('Position outside of grid: {}'.format(ind))
+            raise GridError(f'Position outside of grid: {ind}')
 
     if round_ind:
         rind = numpy.clip(numpy.round(ind).astype(int), 0, self.shape - 1)
@@ -84,17 +84,17 @@ def pos2ind(self,
     """
     r = numpy.squeeze(r)
     if r.size != 3:
-        raise GridError('r must be 3-element vector: {}'.format(r))
+        raise GridError(f'r must be 3-element vector: {r}')
 
     if (which_shifts is not None) and (which_shifts >= self.shifts.shape[0]):
-        raise GridError('Invalid which_shifts: {}'.format(which_shifts))
+        raise GridError(f'Invalid which_shifts: {which_shifts}')
 
     sexyz = self.shifted_exyz(which_shifts)
 
     if check_bounds:
         for a in range(3):
             if self.shape[a] > 1 and (r[a] < sexyz[a][0] or r[a] > sexyz[a][-1]):
-                raise GridError('Position[{}] outside of grid!'.format(a))
+                raise GridError(f'Position[{a}] outside of grid!')
 
     grid_pos = numpy.zeros((3,))
     for a in range(3):